[Blue Tower] Shooting tower, Cost 100

[Green Tower] Slime pit, Cost 150, must be placed in road not in grass

[Yellow Tower] Sniper tower, Cost 200, shoots long range piercing bullet

[Red Tower] Rocket tower, Cost 250, shoots aoe explosive attack.

[1] Select Tower. Keep hitting [1] to go through all tower options.

[2] Upgrade tower. Select upgrades by hitting [2] then click on a tower to spend 250 to upgrade it.